How do I use a function’s return value as a parameter in another function?

I am using Unity 2019.4.20f1

Hi, I am currently trying to dynamically set the Game Object value of a button’s OnClick() method. To do this, I am trying to use a delegate event system, which passes along a reference to the clicked-on-GameObject and a couple of functions.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 // Attatched to InspectMenuController GameObject
 public class InspectMenuController : MonoBehaviour
 {
     private Transform equipTransform;
     private GameObject currentPrefab;
 
     public GameObject useButton;
     public GameObject replaceButton;
 
     private void OnEnable()
     {
         GameEvents.OnMessageSent += SetCurrentPrefab;
     }
     private void OnDisable()
     {
         GameEvents.OnMessageSent -= SetCurrentPrefab;
     }
    
     // This method is called after a GameObject has been clicked on
     // I think it should take the clicked on GameObject reference as a parameter
     // I don't think it is set up correctly
     public void SetCurrentPrefab(GameObject myClickedPrefab)
     {
         GetCurrentPrefab(myClickedPrefab);
     }
 
     // When this function is called by SetCurrentPrefab it should retrun the passed in GameObject parameter as a value
     // I don't think it is set up correctly
     public GameObject GetCurrentPrefab(GameObject myClickedPrefab)
     {
         myClickedPrefab = currentPrefab;
         Debug.Log("Made it to GetCurrentPrefab");
         return currentPrefab;
     }
 
     // This function should be called with a button OnClick method
     // Ideally, it would use the GetCurrentPrefab return value to dynamically set the GameObject value in the OnClick method
     // I don't think it is set up correctly
     public void CenterPrefab(GameObject currentPrefab)
     {
         currentPrefab = GetCurrentPrefab(currentPrefab);
         if (currentPrefab.TryGetComponent(out EquipmentClass equipment))
         {
             // currentPrefab = myClickedPrefab;
             Debug.Log(equipment.Name);
             Debug.Log("Hi CurrentPrefab");
         }
     }
 }
 

My project is set up in a way that everytime a GameObject is clicked, it triggers a delegate event which passes on a reference to the clicked-on-gameObject to all of the event subscribers. When the delegate event is triggered it calls the function SetCurrentPrefab(GameObject myClickedPrefab). I am using this function mainly to call the next function GetCurrentPrefab(GameObject, myClickedPrefab). Both methods’ arguments should be filled by the currently selected GameObject. However, as I type this I am realizing that I probably don’t have this set up correctly. GetCurrentPrefab() would then return a GameObject as a value, and that GameObject should be the GameObject which was passed along with the delegate event.

Finally, CenterPrefab(GameObject currentPrefab) should pass in GetCurrentPrefab()’s return value as a parameter for its currentPrefab argument. I am using the out parameter to access the selected-GameObject’s components.

As it is currently set up, I am given the error: ArgumentException: Object of type 'UnityEngine.Object' cannot be converted to type 'UnityEngine.GameObject'

When I manually set the OnClick() parameter to the GameObject I am currently testing on I get the error: NullReferenceException: Object reference not set to an instance of an object. This error is triggered by line 45, and I think it has something to do with how I’m using the out parameter and the fact that I am probably not passing my GameObject correctly between the previous three functions.

I’m not sure if this is useful but, in the dropdown menu, I only have one option, CenterPrefab( GameObject), rather than the usual two, static and dynamic.

I’m not a competent coder, and there is a good chance a lot of this is nonsense as I’m not always sure if I am correctly using terms and what-not. I would be very thankful for any help!